摘要
研究了SiCP/Ni纳米复合材料的超塑性.SiCP/Ni采用脉冲电沉积方法获得.拉伸实验温度为410℃和450℃,应变速率范围为8.3×10-4～5×10-2s-1.温度为450℃、应变速率为1.67×10-2s-1时,获得的最大延伸率为836%.采用SEM、TEM分析了沉积态材料的表面形貌、断口形貌及变形后的组织,并对变形机理进行了探讨.通过SiC颗粒稳定基体组织有利于实现材料的超塑性,低空洞体积分数有助于获得大延伸率.晶粒长大到微米尺度时,变形机制主要是位错协调的晶界滑移和位错滑移塑性.
Superplasticity of the pulse electrodeposited SiCp/Ni nanocomposite was investigated by tensile tests.Strain rates range from 8.3×10^-4 to 5×10^-2 s^-1, and the selected temperatures are 410℃ and 450℃. A maximum elongation of 836% was obtained at the strain rate of 1.67×10^-2s^-1 and temperature of 450℃. Surface morphology, fracture surfaces and deformed microstructure were observed by SEM and TEM. The deformation mechanism was analyzed. SiC has a favorable effect on the superplasticity of the material by enhancing the microstructural stability. A low volume fraction of cavity was helpful to obtain high elongation. The main deformation mechanisms are dislocation accommodated grain boundary sliding and dislocation slip plasticity when the grains grow to micro size.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2005年第4期68-74,共7页
Acta Materiae Compositae Sinica
关键词
超塑性
电沉积
纳米复合材料
断口
superplasticity
electrodeposition
nanocomposite
fracture surface
